Internal-combustion engine.



H. KNUDSEN.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED NOV. 18, 1911.

Patented Mar. 25, 1913.

law

y x a W /0V@/77or Hans M00860 F HIAQQMV OFFICE.

HANS KNUDSEN, or LONDON, ENGLAND.

INTERNAL-COMBUSTION ENGINE.

Specification of Letters Patent. Application filed November 18, 1911.

Patented Mar. 25, 1913. Serial No. 660,976.

To all whom it ma concern:

Be it known t at I, HANs KNUnsEN, a citizen of the United States of America, residing at Langholm, Clairview Road, Streatham Park, in the county of London, England, have invented useful Improvements in tion Engines, specification.

This invention relates to internal combustion engines, and has for its chief object to prevent the deposit of carbon upon the inner end of the engine piston, which deposit is principally due to the carbonization of the lubricating oil occasioned by the-lat ter coming into contact with the hot surface of the piston. This deposit accumulates in time to a considerable extent, and in addition toits liability of producing pre-ignition, portions of the carbon are liable to become detached from the piston and to be lodged between the valves and their seatings with the result that the working of the Internal-Combusof which the following is a engine is detrimentally affected. According to this invention in order to obviate these objections means are causing a current of air to circulate around the interior of the piston at each stroke of the latter, the saidair being caused to pass from the exterior of the cylinder through theinterior of the piston into the crank case at each in stroke of the piston, and from the crank case against the central portion of the inner end of the piston to the exterior of the cylinder at each out stroke of the piston. To direct the current of cooling air in an efficient manner against the inner end of the piston I provide the latter with an inner wall extending from the outer end of the provided for piston and converging toward the inner end, I where it has a cntral openingthrough which.

the air passes to and fro. The outer piston wall is preferably made. with longitudinal ports arranged to communicate with air ports in the cylinder during part of the piston stroke.

In order that the said invention may be clearly understood and readily carried into effect I will describe the same more fully with reference to the accompanying drawing in which Y Figure l is a vertical section of part-of an engine cylinder and crank casing, and illustrates a convenient construction embodying my invention; Fig. 2 is a vertical section oftthe piston on the line 1-1.

certain new and a considerable striking A is the .piston, and B is the cylinder secured to the crank case C. The piston is made with the inner wall a extending from near the outer end of the piston toward the inner end a and tapering to form an annular chamber a of increasing thickness toward the inner end, where the Wall is formed with a central hole a The outer piston wall has the air ports at extending longitudinally throughout the greater portion of its length and arranged to permit the circulation of air. through the piston for part ofeach stroke, during which the ports 6 in the cylinder B are uncovered and the cooling air flows through an annular chamber a at the upper end of the crank case C. The annular chamber 0 is provided with the opening 0', leading to the atmosphere or to any suitable source of air supply. The air chamber '0 or equivalent air passage may of course be provided in the cylinder itself instead of at the top of the crank case. The cylinder is conveniently secured in the crank case by means of a screw threaded portion 6 receiving nuts or rings 6 which bind against the under side ofa flange c of the crankcase immediately below the air chamber a. The inner end a of the piston, which is the part especially requiring to be cooled, is made as thin as is consistent with safety and may bestrengthened by the also serve to surface.

The cooling operation is efi'ected as follows :The-piston on its in stroke draws air from the exterior into the crank case-C through the ports I) and a, the air passin through the annular piston chamber a an the piston end a, which deflects it into the central hole a of the inner piston walla, whence it flows into the crank case. On the outward stroke the flow is reversed and the air passes, through the central hole a, again striking thepiston end a, and escaping through the annular chamber a and the ports a and Z1. The iston (to-" gether with thegudgeon pin and the work ng parts within the crank case) isthus subinternal ribs a which provide an increased coollng stroke and its temperature is reach ng an excessive height.

The invention can prevented from games such for example as are employed for propelling'aeroplanes and the like, andpar- 1.05 ected to a strong cooling air current at each advantageously he ap f plied to high'speed internal combustion enticularly to that type of engine in which supplementary exhaust ports adapted to be uncovered by the piston at the outer end of its stroke are arranged in direct communication with the atmosphere.

Although in 'the arrangement above described the oirculation of air between the inner and outer Walls of the piston is ef-. fected by the reciprocation of the latter it is to be understood that I do not intend to confine myself solely to this method of producing the circulation.

What I claim and desire to secure by Letters-Patent of the United States is 1. In an internal .combustion engine, a cylinder having ports around its circumference open to cooling atmospheric air, a piston having longitudinal air ports adapted to register throughout the greater part of each stroke with the cylinder air ports, and an inner piston Wall forming an annular chamber in the piston, said inner Wall having a central opening at its outer end so that cooling air flows freely to and fro through the piston in a radial manner during each stroke.

2. In an internal combustion engine, a cylinder having air ports around its circumference, an annular chamber surrounding said air ports and in communication with a supply of cooling atmospheric air, a piston having longitudinal air ports adapted to register throughout the greater part of each stroke with the cylinder air ports, and an inner piston Wall forming an annular chains ber in the piston, said inner Wall having a central opening-at its outer end so that cooling air flows freely to and fro through the piston in a radial manner during each stroke.

In testimony whereof I afiix my signature in presence of two witnesses.

' HANS KNUDSEN.

Witnesses: T. SELBY VVARDLE,

WALTER J. SKERTEN.

Gopies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. G. 

